Hill digram decryption method:

<br>Digram *c1 c2* decrypted as *p1 p2*, where

<br>*p1 = a \* c1* + *b \* c2
<br>p2* = *c \* c1* + *d \* c2*

<br>Enter either *a* and *b* or *c* and *d*.

<br>*Digram Distribution* button:
<br>Same display as *Digram Distribution* button 
on the *Mono* page but for non-overlapping digrams.
